The present invention concerns an instrument and a methodology for the determination of a three-dimensional distribution of the temperatures of dielectric objects, non invasively. It is based on the possibility of measuring, with extreme precision, the electromagnetic heat emission that results from objects with temperatures above absolute zero. All bodies that have such temperature distributions radiate electromagnetic radiation in accordance with the law of Planck: from a physical point of view there is thus a certain quantity of internal heat that is radiated externally as electromagnetic radiation. The power emitted depends principally on the temperature of the body and on its emission properties. The electromagnetic wave emission power of the objects can be described as not very elevated frequencies (until the infrared zone) through Rayleigh-Jeans type equations and it proves to be directly proportional to:                the square of the frequency;        the emission coefficient, between zero and one, that in turn depends on the frequency,        the body temperature; and        the Boltzman constant.        
The emission power however, at room temperature, reaches a maximum in the infrared zone, but decreases, exactly as the square of the frequency, for lower frequencies. Because of this, the detection of the power irradiated by the object in the millimeter, centimeter and meter wavelengths, becomes a much more critical problem and requires extremely sensitive sensors. Surveys that are able to precisely measure the objects' emission power, in this frequency range, have become accessible in the last years. The first surveys in this frequency field were the Dicke radiometers. However, even these sensors have not been greatly used because of the measurement errors introduced principally by the reflection of the radiating power emitted by the objects on the level of the interface between the objects and the sensor's antenna. There have been various attempts to correct this undesired effect. An initial solution to the problem was presented by Ludeke et al. in 1978. More recently, more effective solutions were presented by Troitskii and Raldin, and Holodilov and Ulianichev. The latest generation of sensors, commonly defined as radiothermometers now allows one to measure, with extreme precision, the physical temperature of dielectric objects without errors caused by the reflection of the power that radiates towards the interface between the object and the sensor antenna. In the radiothermometer proposed by the inventors, the antenna is connected through a modulator of the first arm of a circulator. The second arm of this circulator is connected to the input of the radiometer. The radiometer has within itself a reference high tension generator that feeds the modulator. In this case, a resistance, in thermal contact with the temperature transducer, is a noise generator. The output of the resistance is connected both to the output of the radiometer, through a high frequency de-coupling element (inductor), and to the third arm of the circulator through a fitting capacitor. The radiometer stops feeding the resistance when its temperature is identical to the object's temperature.
Ultimately, the problem of detecting electromagnetic emission in the wave length field that goes from millimeters to meters can be considered solved, and the present invention, that will use as electromagnetic radiation sensors the aforementioned radiometers, benefits from this.
The instrument of the present invention requires the extension of the frequencies detectable until the infrared zone. This proves comprehensible if one considers that the penetration power of the electromagnetic waves in the dielectric objects is directly proportional to the wave lengths of the radiation, which in turn inversely depends on the square root of the dielectric constant of the intersected object. When it is desired to map the internal temperature distribution of a determinate object, it is therefore necessary to have at one's disposal detectors that are sensitive to an ample range of frequencies so that measuring the power irradiated in increasing wave lengths, starting from the infrared, deeper and deeper layers of the investigated object are gradually characterized. The necessity of extending the frequency field to the infrared is not a problem because the availability of the infrared sensors is much broader. Even if the instrument of the present invention is useable in all fields in which one wishes to determine the three-dimensional distribution of the temperature within any dielectric object, a particularly important application is the generation of three-dimensional thermal maps in human internal organs, and from this point of view, the instrument is of great interest for medical diagnostics.
In order to illustrate the effect of the invention on the medical diagnostic sphere, and the considerable innovation level, its use will be referred to as Radiomammography, and the instrument will be referred to as a Radiomamograph, that is, an apparatus that is able to produce three dimensional thermal maps of internal sections of the breast. This internal organ is particularly exposed to tumor pathology attacks. Breast cancer is one of the main problems of modern oncology. At the moment, the most used diagnostic method for detection of a breast tumor is X-ray mammography, which has been seriously analyzed, both in its use limitations and its diagnostic criteria. It is a universally recognized fact by this time that x-ray application in mammography currently in use represents an important factor of tumor pathology induction. In 1997, the World Health Organization identified mammography as the third risk factor for breast cancer. Hence, many important world health organizations, such as the Department of Health and Human Services (USA) and the National Cancer Institute (USA) urge the scientific world to develop new methods for the early diagnosis of breast cancer.
For some years now, the possibility of applying, to the detection of breast tumors, techniques such as MRI (Magnetic Resonance Imaging) and PET (Position Emission Tomography) has been investigated. These techniques, however, subject the analyzed organs to strong electromagnetic fields whose effects on the cells are not completely known. Besides, these methodologies, because of their expensiveness and the various limitations that they encounter, cannot be used for population prevention screening.
The mammography technique, in addition to the inconvenience represented by its intrinsic invasiveness and riskiness, presents still another important limiting factor; its low spatial resolution on soft tissues. In the case of breast cancer, its is very difficult to detect tumors whose size is smaller than two centimeters that generally have behind them already a long incubation period.
The present invention proposes, among other things, the solution of the problem of early detection of breast cancer through the application of an investigation method that is able to discover the presence of a tumor in its initial development phase. In particular, the present invention concerns a method and its related instruments for the generation of three-dimensional thermal maps that allow the identification of inflammation centers of tumor masses within tissues even weakly radiating (tenth of degrees). Explicitly referring to the identification of tumor pathologies, it is known that the tumor tissue differs from healthy tissue for a series of biochemical parameters. The tumor cells present a low accumulation efficiency of the metabolic energy that is dispersed thermally, giving rise to a temperature increase of the tumor mass as compared with that of the healthy tissues. It is furthermore acknowledged that any local inflammation is linked to more or less localized temperature increases.